Respect visitation order for proxy packages

crates/uv-resolver/src/dependency_provider.rs

@@ -4,7 +4,7 @@ use pubgrub::{Dependencies, DependencyProvider, PackageResolutionStatistics, Ran
 
 use uv_pep440::Version;
 
-use crate::pubgrub::{PubGrubPackage, PubGrubPriority};
+use crate::pubgrub::{PubGrubPackage, PubGrubPriority, PubGrubTiebreaker};
 use crate::resolver::UnavailableReason;
 
 /// We don't use a dependency provider, we interact with state directly, but we still need this one
@@ -17,8 +17,8 @@ impl DependencyProvider for UvDependencyProvider {
     type V = Version;
     type VS = Range<Version>;
     type M = UnavailableReason;
-    /// Main priority and tiebreak for virtual packages
-    type Priority = (Option<PubGrubPriority>, u32);
+    /// Main priority and tiebreak for virtual packages.
+    type Priority = (Option<PubGrubPriority>, Option<PubGrubTiebreaker>);
     type Err = Infallible;
 
     fn prioritize(

crates/uv-resolver/src/pubgrub/mod.rs

@@ -1,7 +1,7 @@
 pub(crate) use crate::pubgrub::dependencies::PubGrubDependency;
 pub(crate) use crate::pubgrub::distribution::PubGrubDistribution;
 pub(crate) use crate::pubgrub::package::{PubGrubPackage, PubGrubPackageInner, PubGrubPython};
-pub(crate) use crate::pubgrub::priority::{PubGrubPriorities, PubGrubPriority};
+pub(crate) use crate::pubgrub::priority::{PubGrubPriorities, PubGrubPriority, PubGrubTiebreaker};
 pub(crate) use crate::pubgrub::report::PubGrubReportFormatter;
 
 mod dependencies;

crates/uv-resolver/src/pubgrub/priority.rs

@@ -24,7 +24,7 @@ use crate::SentinelRange;
 #[derive(Clone, Debug, Default)]
 pub(crate) struct PubGrubPriorities {
     package_priority: FxHashMap<PackageName, PubGrubPriority>,
-    virtual_package_tiebreaker: FxHashMap<PubGrubPackage, u32>,
+    virtual_package_tiebreaker: FxHashMap<PubGrubPackage, PubGrubTiebreaker>,
 }
 
 impl PubGrubPriorities {
@@ -38,8 +38,10 @@ impl PubGrubPriorities {
         if !self.virtual_package_tiebreaker.contains_key(package) {
             self.virtual_package_tiebreaker.insert(
                 package.clone(),
-                u32::try_from(self.virtual_package_tiebreaker.len())
-                    .expect("Less than 2**32 packages"),
+                PubGrubTiebreaker::from(
+                    u32::try_from(self.virtual_package_tiebreaker.len())
+                        .expect("Less than 2**32 packages"),
+                ),
             );
         }
 
@@ -104,26 +106,25 @@ impl PubGrubPriorities {
             | PubGrubPriority::ConflictEarly(Reverse(index))
             | PubGrubPriority::Singleton(Reverse(index))
             | PubGrubPriority::DirectUrl(Reverse(index)) => Some(*index),
-            PubGrubPriority::Proxy | PubGrubPriority::Root => None,
+            PubGrubPriority::Root => None,
         }
     }
 
     /// Return the [`PubGrubPriority`] of the given package, if it exists.
-    pub(crate) fn get(&self, package: &PubGrubPackage) -> (Option<PubGrubPriority>, u32) {
+    pub(crate) fn get(
+        &self,
+        package: &PubGrubPackage,
+    ) -> (Option<PubGrubPriority>, Option<PubGrubTiebreaker>) {
         let package_priority = match &**package {
             PubGrubPackageInner::Root(_) => Some(PubGrubPriority::Root),
             PubGrubPackageInner::Python(_) => Some(PubGrubPriority::Root),
-            PubGrubPackageInner::Marker { .. } => Some(PubGrubPriority::Proxy),
-            PubGrubPackageInner::Extra { .. } => Some(PubGrubPriority::Proxy),
-            PubGrubPackageInner::Dev { .. } => Some(PubGrubPriority::Proxy),
+            PubGrubPackageInner::Marker { name, .. } => self.package_priority.get(name).copied(),
+            PubGrubPackageInner::Extra { name, .. } => self.package_priority.get(name).copied(),
+            PubGrubPackageInner::Dev { name, .. } => self.package_priority.get(name).copied(),
             PubGrubPackageInner::Package { name, .. } => self.package_priority.get(name).copied(),
         };
-        let virtual_package_tiebreaker = self
-            .virtual_package_tiebreaker
-            .get(package)
-            .copied()
-            .unwrap_or_default();
-        (package_priority, virtual_package_tiebreaker)
+        let package_tiebreaker = self.virtual_package_tiebreaker.get(package).copied();
+        (package_priority, package_tiebreaker)
     }
 
     /// Mark a package as prioritized by setting it to [`PubGrubPriority::ConflictEarly`], if it
@@ -225,13 +226,15 @@ pub(crate) enum PubGrubPriority {
     /// [`ForkUrls`].
     DirectUrl(Reverse<usize>),
 
-    /// The package is a proxy package.
-    ///
-    /// We process proxy packages eagerly since each proxy package expands into two "regular"
-    /// [`PubGrubPackage`] packages, which gives us additional constraints while not affecting the
-    /// priorities (since the expanded dependencies are all linked to the same package name).
-    Proxy,
-
     /// The package is the root package.
     Root,
 }
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub(crate) struct PubGrubTiebreaker(Reverse<u32>);
+
+impl From<u32> for PubGrubTiebreaker {
+    fn from(value: u32) -> Self {
+        Self(Reverse(value))
+    }
+}

crates/uv-resolver/src/resolver/mod.rs

@@ -2301,16 +2301,16 @@ impl<InstalledPackages: InstalledPackagesProvider> ResolverState<InstalledPackag
                     }
                 }
 
+                // Verify that the package is allowed under the hash-checking policy.
+                if !self
+                    .hasher
+                    .allows_package(candidate.name(), candidate.version())
+                {
+                    return Ok(None);
+                }
+
                 // Emit a request to fetch the metadata for this version.
                 if self.index.distributions().register(candidate.version_id()) {
-                    // Verify that the package is allowed under the hash-checking policy.
-                    if !self
-                        .hasher
-                        .allows_package(candidate.name(), candidate.version())
-                    {
-                        return Err(ResolveError::UnhashedPackage(candidate.name().clone()));
-                    }
-
                     let dist = dist.for_resolution().to_owned();
 
                     let response = match dist {
@@ -2600,9 +2600,7 @@ impl ForkState {
                 }
             }
 
-            let for_package = &self.pubgrub.package_store[for_package];
-
-            if let Some(name) = for_package
+            if let Some(name) = self.pubgrub.package_store[for_package]
                 .name_no_root()
                 .filter(|name| !workspace_members.contains(name))
             {
@@ -2633,9 +2631,7 @@ impl ForkState {
             }
 
             // Update the package priorities.
-            if !for_package.is_proxy() {
-                self.priorities.insert(package, version, &self.fork_urls);
-            }
+            self.priorities.insert(package, version, &self.fork_urls);
         }
 
         let conflict = self.pubgrub.add_package_version_dependencies(

crates/uv/tests/it/lock_conflict.rs

@@ -50,7 +50,7 @@ fn extra_basic() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[extra1] depends on sortedcontainers==2.3.0 and project[extra2] depends on sortedcontainers==2.4.0, we can conclude that project[extra1] and project[extra2] are incompatible.
+      ╰─▶ Because project[extra2] depends on sortedcontainers==2.4.0 and project[extra1] depends on sortedcontainers==2.3.0, we can conclude that project[extra1] and project[extra2] are incompatible.
           And because your project requires project[extra1] and project[extra2], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
@@ -250,8 +250,8 @@ fn extra_basic_three_extras() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[extra2] depends on sortedcontainers==2.3.0 and project[project3] depends on sortedcontainers==2.4.0, we can conclude that project[extra2] and project[project3] are incompatible.
-          And because your project requires project[extra2] and project[project3], we can conclude that your project's requirements are unsatisfiable.
+      ╰─▶ Because project[extra2] depends on sortedcontainers==2.3.0 and project[extra1] depends on sortedcontainers==2.2.0, we can conclude that project[extra1] and project[extra2] are incompatible.
+          And because your project requires project[extra1] and project[extra2], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
     // And now with the same extra configuration, we tell uv about
@@ -538,8 +538,8 @@ fn extra_multiple_not_conflicting2() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[project3] depends on sortedcontainers==2.3.0 and project[project4] depends on sortedcontainers==2.4.0, we can conclude that project[project3] and project[project4] are incompatible.
-          And because your project requires project[project3] and project[project4], we can conclude that your project's requirements are unsatisfiable.
+      ╰─▶ Because project[extra2] depends on sortedcontainers==2.4.0 and project[extra1] depends on sortedcontainers==2.3.0, we can conclude that project[extra1] and project[extra2] are incompatible.
+          And because your project requires project[extra1] and project[extra2], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
     // If we define extra1/extra2 as conflicting and project3/project4
@@ -582,7 +582,7 @@ fn extra_multiple_not_conflicting2() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[extra2] depends on sortedcontainers==2.4.0 and project[project3] depends on sortedcontainers==2.3.0, we can conclude that project[extra2] and project[project3] are incompatible.
+      ╰─▶ Because project[project3] depends on sortedcontainers==2.3.0 and project[extra2] depends on sortedcontainers==2.4.0, we can conclude that project[extra2] and project[project3] are incompatible.
           And because your project requires project[extra2] and project[project3], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
@@ -715,8 +715,8 @@ fn extra_multiple_independent() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[project3] depends on anyio==4.1.0 and project[project4] depends on anyio==4.2.0, we can conclude that project[project3] and project[project4] are incompatible.
-          And because your project requires project[project3] and project[project4], we can conclude that your project's requirements are unsatisfiable.
+      ╰─▶ Because project[extra2] depends on sortedcontainers==2.4.0 and project[extra1] depends on sortedcontainers==2.3.0, we can conclude that project[extra1] and project[extra2] are incompatible.
+          And because your project requires project[extra1] and project[extra2], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
     // OK, responding to the error, we declare our anyio extras
@@ -755,7 +755,7 @@ fn extra_multiple_independent() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[extra1] depends on sortedcontainers==2.3.0 and project[extra2] depends on sortedcontainers==2.4.0, we can conclude that project[extra1] and project[extra2] are incompatible.
+      ╰─▶ Because project[extra2] depends on sortedcontainers==2.4.0 and project[extra1] depends on sortedcontainers==2.3.0, we can conclude that project[extra1] and project[extra2] are incompatible.
           And because your project requires project[extra1] and project[extra2], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
@@ -1047,7 +1047,7 @@ fn extra_config_change_ignore_lockfile() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[extra1] depends on sortedcontainers==2.3.0 and project[extra2] depends on sortedcontainers==2.4.0, we can conclude that project[extra1] and project[extra2] are incompatible.
+      ╰─▶ Because project[extra2] depends on sortedcontainers==2.4.0 and project[extra1] depends on sortedcontainers==2.3.0, we can conclude that project[extra1] and project[extra2] are incompatible.
           And because your project requires project[extra1] and project[extra2], we can conclude that your project's requirements are unsatisfiable.
     "###);
 
@@ -1289,9 +1289,11 @@ fn extra_nested_across_workspace() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because proxy1[extra1]==0.1.0 depends on anyio==4.1.0 and proxy1[extra2]==0.1.0 depends on anyio==4.2.0, we can conclude that proxy1[extra1]==0.1.0 and proxy1[extra2]==0.1.0 are incompatible.
-          And because only proxy1[extra1]==0.1.0 is available and dummysub[extra1] depends on proxy1[extra1], we can conclude that dummysub[extra1] and proxy1[extra2]==0.1.0 are incompatible.
-          And because only proxy1[extra2]==0.1.0 is available and dummy[extra2] depends on proxy1[extra2], we can conclude that dummy[extra2] and dummysub[extra1] are incompatible.
+      ╰─▶ Because dummy[extra2] depends on proxy1[extra2] and only proxy1[extra2]==0.1.0 is available, we can conclude that dummy[extra2] depends on proxy1[extra2]==0.1.0. (1)
+
+          Because proxy1[extra1]==0.1.0 depends on anyio==4.1.0 and proxy1[extra2]==0.1.0 depends on anyio==4.2.0, we can conclude that proxy1[extra1]==0.1.0 and proxy1[extra2]==0.1.0 are incompatible.
+          And because we know from (1) that dummy[extra2] depends on proxy1[extra2]==0.1.0, we can conclude that dummy[extra2] and proxy1[extra1]==0.1.0 are incompatible.
+          And because only proxy1[extra1]==0.1.0 is available and dummysub[extra1] depends on proxy1[extra1], we can conclude that dummysub[extra1] and dummy[extra2] are incompatible.
           And because your workspace requires dummy[extra2] and dummysub[extra1], we can conclude that your workspace's requirements are unsatisfiable.
     "###);
 
@@ -1415,7 +1417,7 @@ fn group_basic() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project:group1 depends on sortedcontainers==2.3.0 and project:group2 depends on sortedcontainers==2.4.0, we can conclude that project:group1 and project:group2 are incompatible.
+      ╰─▶ Because project:group2 depends on sortedcontainers==2.4.0 and project:group1 depends on sortedcontainers==2.3.0, we can conclude that project:group1 and project:group2 are incompatible.
           And because your project requires project:group1 and project:group2, we can conclude that your project's requirements are unsatisfiable.
     "###);
 
@@ -1793,7 +1795,7 @@ fn mixed() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because project[extra1] depends on sortedcontainers==2.4.0 and project:group1 depends on sortedcontainers==2.3.0, we can conclude that project:group1 and project[extra1] are incompatible.
+      ╰─▶ Because project:group1 depends on sortedcontainers==2.3.0 and project[extra1] depends on sortedcontainers==2.4.0, we can conclude that project:group1 and project[extra1] are incompatible.
           And because your project requires project[extra1] and project:group1, we can conclude that your project's requirements are unsatisfiable.
     "###);
 
@@ -7126,8 +7128,8 @@ fn overlapping_resolution_markers() -> Result<()> {
             "sys_platform == 'linux' and extra != 'extra-14-ads-mega-model-cpu' and extra == 'extra-14-ads-mega-model-cu118'",
             "sys_platform != 'linux' and extra != 'extra-14-ads-mega-model-cpu' and extra == 'extra-14-ads-mega-model-cu118'",
             "platform_machine != 'aarch64' and sys_platform == 'linux' and extra == 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",
-            "sys_platform != 'darwin' and sys_platform != 'linux' and extra == 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",
             "platform_machine == 'aarch64' and sys_platform == 'linux' and extra == 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",
+            "sys_platform != 'darwin' and sys_platform != 'linux' and extra == 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",
             "sys_platform == 'darwin' and extra == 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",
             "sys_platform == 'linux' and extra != 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",
             "sys_platform != 'linux' and extra != 'extra-14-ads-mega-model-cpu' and extra != 'extra-14-ads-mega-model-cu118'",

crates/uv/tests/it/lock_scenarios.rs

@@ -2940,7 +2940,7 @@ fn fork_non_local_fork_marker_direct() -> Result<()> {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because package-b==1.0.0 depends on package-c>=2.0.0 and package-a==1.0.0 depends on package-c<2.0.0, we can conclude that package-a==1.0.0 and package-b==1.0.0 are incompatible.
+      ╰─▶ Because package-a==1.0.0 depends on package-c<2.0.0 and package-b==1.0.0 depends on package-c>=2.0.0, we can conclude that package-a{sys_platform == 'linux'}==1.0.0 and package-b{sys_platform == 'darwin'}==1.0.0 are incompatible.
           And because your project depends on package-a{sys_platform == 'linux'}==1.0.0 and package-b{sys_platform == 'darwin'}==1.0.0, we can conclude that your project's requirements are unsatisfiable.
     "###
     );
@@ -3015,10 +3015,8 @@ fn fork_non_local_fork_marker_transitive() -> Result<()> {
       ╰─▶ Because package-a==1.0.0 depends on package-c{sys_platform == 'linux'}<2.0.0 and only the following versions of package-c{sys_platform == 'linux'} are available:
               package-c{sys_platform == 'linux'}==1.0.0
               package-c{sys_platform == 'linux'}>2.0.0
-          we can conclude that package-a==1.0.0 depends on package-c{sys_platform == 'linux'}==1.0.0. (1)
-
-          Because only package-c{sys_platform == 'darwin'}<=2.0.0 is available and package-b==1.0.0 depends on package-c{sys_platform == 'darwin'}>=2.0.0, we can conclude that package-b==1.0.0 depends on package-c==2.0.0.
-          And because we know from (1) that package-a==1.0.0 depends on package-c{sys_platform == 'linux'}==1.0.0, we can conclude that package-a==1.0.0 and package-b==1.0.0 are incompatible.
+          we can conclude that package-a==1.0.0 depends on package-c{sys_platform == 'linux'}==1.0.0.
+          And because only package-c{sys_platform == 'darwin'}<=2.0.0 is available and package-b==1.0.0 depends on package-c{sys_platform == 'darwin'}>=2.0.0, we can conclude that package-a==1.0.0 and package-b==1.0.0 are incompatible.
           And because your project depends on package-a==1.0.0 and package-b==1.0.0, we can conclude that your project's requirements are unsatisfiable.
     "###
     );